Articles | Volume 14, issue 11
https://doi.org/10.5194/amt-14-7199-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-14-7199-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Nov 2021
Research article |
| 17 Nov 2021
| 17 Nov 2021
Four-dimensional mesospheric and lower thermospheric wind fields using Gaussian process regression on multistatic specular meteor radar observations
Haystack Observatory, Massachusetts Institute of Technology, Westford, MA 01886, USA
Jorge L. Chau
Leibniz Institute of Atmospheric Physics, University of Rostock, 18225 Kühlungsborn, Germany
Philip J. Erickson
Haystack Observatory, Massachusetts Institute of Technology, Westford, MA 01886, USA
Juha P. Vierinen
Department of Physics and Technology, UiT Arctic University of Norway, 9010 Tromsø, Norway
J. Miguel Urco
Leibniz Institute of Atmospheric Physics, University of Rostock, 18225 Kühlungsborn, Germany
Matthias Clahsen
Leibniz Institute of Atmospheric Physics, University of Rostock, 18225 Kühlungsborn, Germany
Related authors
Jorge Luis Chau, Juan Miguel Urco, Juha Pekka Vierinen, Ryan Andrew Volz, Matthias Clahsen, Nico Pfeffer, and Jörg Trautner
Atmos. Meas. Tech., 12, 2113–2127, https://doi.org/10.5194/amt-12-2113-2019, https://doi.org/10.5194/amt-12-2113-2019, 2019
Short summary
Short summary
New systems to study the mesosphere are introduced. They result from the reengineering of previous systems, by making use of MIMO, spread-spectrum and compressed-sensing techniques that are widely used in telecommunications. The interferometer configuration is now implemented in transmission, making the location of meteor echoes possible with just one antenna on reception. Our novel concept makes the study of a mesosphere volume from different viewing points on the ground feasible and easy.
Claire Trop, James LaBelle, Philip Erickson, Shun-Rong Zhang, David McGaw, and Terrence Kovacs
EGUsphere, https://doi.org/10.5194/egusphere-2024-2383, https://doi.org/10.5194/egusphere-2024-2383, 2024
Short summary
Short summary
Traveling Ionospheric Disturbances (TIDs) are manifestations of atmospheric waves that are significant for transfer of energy and momentum between atmospheric layers and regions. This work demonstrates that velocities and directions of TIDs can be measured by monitoring the tiny shift in frequency of AM radio signals when they reflect from a moving ionosphere, and that this method can be scaled to use large numbers of radio receivers and transmitters to monitor TIDs on a continental scale.
Jennifer Hartisch, Jorge L. Chau, Ralph Latteck, Toralf Renkwitz, and Marius Zecha
Ann. Geophys., 42, 29–43, https://doi.org/10.5194/angeo-42-29-2024, https://doi.org/10.5194/angeo-42-29-2024, 2024
Short summary
Short summary
Scientists are studying the mesosphere and lower thermosphere using radar in northern Norway. They found peculiar events with strong upward and downward air movements, happening frequently (up to 2.5 % per month) from 2015 to 2021. Over 700 such events were noted, lasting around 20 min and expanding the studied layer. A total of 17 % of these events had extreme vertical speeds, showing their unique nature.
Juliana Jaen, Toralf Renkwitz, Huixin Liu, Christoph Jacobi, Robin Wing, Aleš Kuchař, Masaki Tsutsumi, Njål Gulbrandsen, and Jorge L. Chau
Atmos. Chem. Phys., 23, 14871–14887, https://doi.org/10.5194/acp-23-14871-2023, https://doi.org/10.5194/acp-23-14871-2023, 2023
Short summary
Short summary
Investigation of winds is important to understand atmospheric dynamics. In the summer mesosphere and lower thermosphere, there are three main wind flows: the mesospheric westward, the mesopause southward (equatorward), and the lower-thermospheric eastward wind. Combining almost 2 decades of measurements from different radars, we study the trend, their interannual oscillations, and the effects of the geomagnetic activity over these wind maxima.
Kristina Collins, Steve Cerwin, Philip Erickson, Dev Joshi, Nathaniel Frissell, and Joe Huba
EGUsphere, https://doi.org/10.5194/egusphere-2022-327, https://doi.org/10.5194/egusphere-2022-327, 2022
Preprint archived
Short summary
Short summary
Radio measurements of time standard stations can be used to measure changes in the ionosphere's height, but not the height itself. In this paper, we show that we can estimate ionospheric height using data from amateur radio stations along with other systems and simulations, that multiple signal paths can be found in this data, and that precisely controlling the receiver frequency is important for this approach to work. This work will help us analyze radio data collected by citizen scientists.
Sumanta Sarkhel, Gunter Stober, Jorge L. Chau, Steven M. Smith, Christoph Jacobi, Subarna Mondal, Martin G. Mlynczak, and James M. Russell III
Ann. Geophys., 40, 179–190, https://doi.org/10.5194/angeo-40-179-2022, https://doi.org/10.5194/angeo-40-179-2022, 2022
Short summary
Short summary
A rare gravity wave event was observed on the night of 25 April 2017 over northern Germany. An all-sky airglow imager recorded an upward-propagating wave at different altitudes in mesosphere with a prominent wave front above 91 km and faintly observed below. Based on wind and satellite-borne temperature profiles close to the event location, we have found the presence of a leaky thermal duct layer in 85–91 km. The appearance of this duct layer caused the wave amplitudes to diminish below 91 km.
Juliana Jaen, Toralf Renkwitz, Jorge L. Chau, Maosheng He, Peter Hoffmann, Yosuke Yamazaki, Christoph Jacobi, Masaki Tsutsumi, Vivien Matthias, and Chris Hall
Ann. Geophys., 40, 23–35, https://doi.org/10.5194/angeo-40-23-2022, https://doi.org/10.5194/angeo-40-23-2022, 2022
Short summary
Short summary
To study long-term trends in the mesosphere and lower thermosphere (70–100 km), we established two summer length definitions and analyzed the variability over the years (2004–2020). After the analysis, we found significant trends in the summer beginning of one definition. Furthermore, we were able to extend one of the time series up to 31 years and obtained evidence of non-uniform trends and periodicities similar to those known for the quasi-biennial oscillation and El Niño–Southern Oscillation.
Fabio Vargas, Jorge L. Chau, Harikrishnan Charuvil Asokan, and Michael Gerding
Atmos. Chem. Phys., 21, 13631–13654, https://doi.org/10.5194/acp-21-13631-2021, https://doi.org/10.5194/acp-21-13631-2021, 2021
Short summary
Short summary
We study large- and small-scale gravity wave cases observed in both airglow imagery and meteor radar data obtained during the SIMONe campaign carried out in early November 2018. We calculate the intrinsic features of several waves and estimate their impact in the mesosphere and lower thermosphere region via transferring energy and momentum to the atmosphere. We also associate cases of large-scale waves with secondary wave generation in the stratosphere.
Johann Stamm, Juha Vierinen, Juan M. Urco, Björn Gustavsson, and Jorge L. Chau
Ann. Geophys., 39, 119–134, https://doi.org/10.5194/angeo-39-119-2021, https://doi.org/10.5194/angeo-39-119-2021, 2021
Harikrishnan Charuvil Asokan, Jorge L. Chau, Raffaele Marino, Juha Vierinen, Fabio Vargas, Juan Miguel Urco, Matthias Clahsen, and Christoph Jacobi
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-974, https://doi.org/10.5194/acp-2020-974, 2020
Preprint withdrawn
Short summary
Short summary
This paper explores the dynamics of gravity waves and turbulence present in the mesosphere and lower thermosphere (MLT) region. We utilized two different techniques on meteor radar observations and simulations to obtain power spectra at different horizontal scales. The techniques are applied to a special campaign conducted in northern Germany in November 2018. The study revealed the dominance of large-scale structures with horizontal scales larger than 500 km during the campaign period.
Alex T. Chartier, Juha Vierinen, and Geonhwa Jee
Atmos. Meas. Tech., 13, 3023–3031, https://doi.org/10.5194/amt-13-3023-2020, https://doi.org/10.5194/amt-13-3023-2020, 2020
Short summary
Short summary
A novel oblique ionospheric radio sounder has been developed and demonstrated in Antarctica. The transmitter was located at McMurdo and the receiver at the South Pole (1356 km great-circle path). The system cycled through 12 frequencies each minute and recorded signal time of flight, intensity, and Doppler. This allowed for the estimation of peak ionospheric electron density, which validated well against independent data from the nearby Jang Bogo ionosonde and GPS TEC.
Maosheng He and Jorge Luis Chau
Atmos. Chem. Phys., 19, 5993–6006, https://doi.org/10.5194/acp-19-5993-2019, https://doi.org/10.5194/acp-19-5993-2019, 2019
Short summary
Short summary
We propose an approach to resolve waves with multiple spatial scales at a given frequency using ground-based detectors from few longitudinal sectors. The approach is used to investigate near-12 h waves. Results suggest that broadly reported enhancements of two solar nonmigrating tides during sudden stratospheric warming events are just low-frequency-resolved signatures of two neighboring waves. The tides do not enhance.
Dimitry Pokhotelov, Gunter Stober, and Jorge Luis Chau
Atmos. Chem. Phys., 19, 5251–5258, https://doi.org/10.5194/acp-19-5251-2019, https://doi.org/10.5194/acp-19-5251-2019, 2019
Short summary
Short summary
Twelve years of radar observations from a mid-latitude location in Kühlungsborn, Germany have been analysed to study characteristics of mesospheric summer echoes (MSEs). The statistical analysis shows that MSEs have a strong daytime preference and early summer seasonal preference. It is demonstrated that the meridional wind transport from polar regions is the important controlling factor for MSEs, while no clear connection to geomagnetic and solar activity is found.
Fazlul I. Laskar, Gunter Stober, Jens Fiedler, Meers M. Oppenheim, Jorge L. Chau, Duggirala Pallamraju, Nicholas M. Pedatella, Masaki Tsutsumi, and Toralf Renkwitz
Atmos. Chem. Phys., 19, 5259–5267, https://doi.org/10.5194/acp-19-5259-2019, https://doi.org/10.5194/acp-19-5259-2019, 2019
Short summary
Short summary
Meteor radars are used to track and estimate the fading time of meteor trails. In this investigation, it is observed that the diffusion time estimated from such trail fading time is anomalously higher during noctilucent clouds (NLC) than that in its absence. We propose that NLC particles absorb background electrons and thus modify the background electrodynamics, leading to such an anomaly.
Jorge Luis Chau, Juan Miguel Urco, Juha Pekka Vierinen, Ryan Andrew Volz, Matthias Clahsen, Nico Pfeffer, and Jörg Trautner
Atmos. Meas. Tech., 12, 2113–2127, https://doi.org/10.5194/amt-12-2113-2019, https://doi.org/10.5194/amt-12-2113-2019, 2019
Short summary
Short summary
New systems to study the mesosphere are introduced. They result from the reengineering of previous systems, by making use of MIMO, spread-spectrum and compressed-sensing techniques that are widely used in telecommunications. The interferometer configuration is now implemented in transmission, making the location of meteor echoes possible with just one antenna on reception. Our novel concept makes the study of a mesosphere volume from different viewing points on the ground feasible and easy.
Nikoloz Gudadze, Gunter Stober, and Jorge L. Chau
Atmos. Chem. Phys., 19, 4485–4497, https://doi.org/10.5194/acp-19-4485-2019, https://doi.org/10.5194/acp-19-4485-2019, 2019
Short summary
Short summary
We show a possibility of measuring mean vertical winds during the summer months using polar mesosphere summer echo (PMSE) observations. Middle Atmosphere Alomar Radar System observations of PMSE five-beam radial velocities are analysed to obtain the results. We found that sampling issues are the reason for bias in vertical wind measurements at the edges of PMSE altitudes. However, the PMSE is a good tracer for the mean vertical wind estimation at the central altitudes with its peak occurrence.
Juan Miguel Urco, Jorge Luis Chau, Tobias Weber, and Ralph Latteck
Atmos. Meas. Tech., 12, 955–969, https://doi.org/10.5194/amt-12-955-2019, https://doi.org/10.5194/amt-12-955-2019, 2019
Short summary
Short summary
For decades, radar observations have been used to study complicated atmospheric dynamics. Previous observations of the mesosphere, between 80 and 90 km altitude, over polar regions have been limited to a spatial resolution of a few kilometers. In this work, we present a technique which allows 3-D radar observations of the mesospheric dynamics, with an unprecedented spatial resolution of ~ 900 m. We combine the concept of MIMO and high-resolution algorithms to improve the spatial resolution.
Gunter Stober, Jorge L. Chau, Juha Vierinen, Christoph Jacobi, and Sven Wilhelm
Atmos. Meas. Tech., 11, 4891–4907, https://doi.org/10.5194/amt-11-4891-2018, https://doi.org/10.5194/amt-11-4891-2018, 2018
J. Federico Conte, Jorge L. Chau, Fazlul I. Laskar, Gunter Stober, Hauke Schmidt, and Peter Brown
Ann. Geophys., 36, 999–1008, https://doi.org/10.5194/angeo-36-999-2018, https://doi.org/10.5194/angeo-36-999-2018, 2018
Short summary
Short summary
Based on comparisons of meteor radar measurements with HAMMONIA model simulations, we show that the differences exhibited by the semidiurnal solar tide (S2) observed at middle and high latitudes of the Northern Hemisphere between equinox times are mainly due to distinct behaviors of the migrating semidiurnal (SW2) and the non-migrating westward-propagating wave number 1 semidiurnal (SW1) tidal components.
Jorge L. Chau, Derek McKay, Juha P. Vierinen, Cesar La Hoz, Thomas Ulich, Markku Lehtinen, and Ralph Latteck
Atmos. Chem. Phys., 18, 9547–9560, https://doi.org/10.5194/acp-18-9547-2018, https://doi.org/10.5194/acp-18-9547-2018, 2018
Short summary
Short summary
Combining a phased-array power radar and a phased-array radio telescope, we have been able to identify and characterized horizontal structures and movement of noctilucent clouds, but at 3 m scales instead of optical scales. As a byproduct of our observations, we have studied their angular dependence. We show a new alternative to study these clouds on routine basis and therefore study the atmospheric dynamics that modulate them.
Dimitry Pokhotelov, Erich Becker, Gunter Stober, and Jorge L. Chau
Ann. Geophys., 36, 825–830, https://doi.org/10.5194/angeo-36-825-2018, https://doi.org/10.5194/angeo-36-825-2018, 2018
Short summary
Short summary
Atmospheric tides are produced by solar heating of the lower atmosphere. The tides propagate to the upper atmosphere and ionosphere playing an important role in the vertical coupling. Ground radar measurements of the seasonal variability of tides are compared with global numerical simulations. The agreement with radar data and limitations of the numerical model are discussed. The work represents a first step in modelling the impact of tidal dynamics on the upper atmosphere and ionosphere.
Gunter Stober, Svenja Sommer, Carsten Schult, Ralph Latteck, and Jorge L. Chau
Atmos. Chem. Phys., 18, 6721–6732, https://doi.org/10.5194/acp-18-6721-2018, https://doi.org/10.5194/acp-18-6721-2018, 2018
Sven Wilhelm, Gunter Stober, and Jorge L. Chau
Ann. Geophys., 35, 893–906, https://doi.org/10.5194/angeo-35-893-2017, https://doi.org/10.5194/angeo-35-893-2017, 2017
Short summary
Short summary
A comparison between winds and tides in the mesosphere and lower thermosphere based on measurements from a meteor radar (MR) and a medium-frequency radar in northern Norway was done to estimate potential biases between the two systems. Our results indicate reasonable agreement for the zonal and meridional wind components between 78 and 92 km. Based on these findings, we have taken the MR data as a reference and thus construct a consistent and homogenous wind from approximately 60 to 110 km.
Gunter Stober, Vivien Matthias, Christoph Jacobi, Sven Wilhelm, Josef Höffner, and Jorge L. Chau
Ann. Geophys., 35, 711–720, https://doi.org/10.5194/angeo-35-711-2017, https://doi.org/10.5194/angeo-35-711-2017, 2017
Svenja Sommer and Jorge L. Chau
Ann. Geophys., 34, 1231–1241, https://doi.org/10.5194/angeo-34-1231-2016, https://doi.org/10.5194/angeo-34-1231-2016, 2016
Short summary
Short summary
Radar echoes from mesospheric altitudes (80–90 km) are called polar mesospheric summer echoes (PMSEs). These echoes can be used to derive wind velocities and turbulence strength estimations in a region where measurements are hard to perform. The small-scale structure of PMSEs has not been analysed before but, as we will show, has a major influence on wind and turbulence measurements. We also present a method to improve these measurements by using software beam-steering methods.
Juha Vierinen, Jorge L. Chau, Nico Pfeffer, Matthias Clahsen, and Gunter Stober
Atmos. Meas. Tech., 9, 829–839, https://doi.org/10.5194/amt-9-829-2016, https://doi.org/10.5194/amt-9-829-2016, 2016
Short summary
Short summary
This paper describes the use of pseudorandom coded continuous wave radar transmissions for meteor radar. This avoids range-aliased echoes, maximizes pulse compression gain, is less susceptible to RFI, allows time resolution to be changed flexibly, and enables multiple transmitters to operate on the same frequency without interfering each other. These features make the radar well suited for multi-static meteor radar networks. We show results from a measurement campaign to demonstrate the method.
S. Sommer, G. Stober, J. L. Chau, and R. Latteck
Adv. Radio Sci., 12, 197–203, https://doi.org/10.5194/ars-12-197-2014, https://doi.org/10.5194/ars-12-197-2014, 2014
C. Schult, G. Stober, J. L. Chau, and R. Latteck
Ann. Geophys., 31, 1843–1851, https://doi.org/10.5194/angeo-31-1843-2013, https://doi.org/10.5194/angeo-31-1843-2013, 2013
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: Remote Sensing | Topic: Data Processing and Information Retrieval
Global Navigation Satellite System (GNSS) radio occultation climatologies mapped by machine learning and Bayesian interpolation
Determination of low-level temperature profiles from microwave radiometer observations during rain
Aeolus lidar surface return (LSR) at 355 nm as a new Aeolus Level-2A product
Sampling the diurnal and annual cycles of the Earth's energy imbalance with constellations of satellite-borne radiometers
Retrieval of top-of-atmosphere fluxes from combined EarthCARE lidar, imager, and broadband radiometer observations: the BMA-FLX product
Analysis of the measurement uncertainty for a 3D wind lidar
Improving solution availability and temporal consistency of an optimal-estimation physical retrieval for ground-based thermodynamic boundary layer profiling
An improved geolocation methodology for spaceborne radar and lidar systems
Combining low- and high-frequency microwave radiometer measurements from the MOSAiC expedition for enhanced water vapour products
HAMSTER: Hyperspectral Albedo Maps dataset with high Spatial and TEmporal Resolution
Global-scale gravity wave analysis methodology for the ESA Earth Explorer 11 candidate CAIRT
Retrieval of pseudo-BRDF-adjusted surface reflectance at 440 nm from the Geostationary Environmental Monitoring Spectrometer (GEMS)
Benchmarking KDP in Rainfall: A Quantitative Assessment of Estimation Algorithms Using C-Band Weather Radar Observations
Drop size distribution retrieval using dual-polarization radar at C-band and S-band
Thermal tides in the middle atmosphere at mid-latitudes measured with a ground-based microwave radiometer
Mitigating Radome Induced Bias in X-Band Weather Radar Polarimetric moments using Adaptive DFT Algorithm
Global sensitivity analysis of simulated remote sensing polarimetric observations over snow
Improving the Gaussianity of radar reflectivity departures between observations and simulations using symmetric rain rates
On the temperature stability requirements of free-running Nd:YAG lasers for atmospheric temperature profiling through the rotational Raman technique
Limitations in wavelet analysis of non-stationary atmospheric gravity wave signatures in temperature profiles
A new non-linearity correction method for the spectrum from the Geostationary Inferometric Infrared Sounder on board Fengyun-4 satellites and its preliminary assessments
Determination of high-precision tropospheric delays using crowdsourced smartphone GNSS data
Unfiltering of the EarthCARE Broadband Radiometer (BBR) observations: the BM-RAD product
Variance estimations in the presence of intermittent interference and their applications to incoherent scatter radar signal processing
A clustering-based method for identifying and tracking squall lines
A multi-instrument fuzzy logic boundary-layer-top detection algorithm
Sensitivity of thermodynamic profiles retrieved from ground-based microwave and infrared observations to additional input data from active remote sensing instruments and numerical weather prediction models
Scale separation for gravity wave analysis from 3D temperature observations in the mesosphere and lower thermosphere (MLT) region
Estimating the refractivity bias of FORMOSAT-7/COSMIC-2 Global Navigation Satellite System (GNSS) radio occultation in the deep troposphere
High Spectral Resolution Lidar – generation 2 (HSRL-2) retrievals of ocean surface wind speed: methodology and evaluation
Dual adaptive differential threshold method for automated detection of faint and strong echo features in radar observations of winter storms
Noise filtering options for conically scanning Doppler lidar measurements with low pulse accumulation
Comparative experimental validation of microwave hyperspectral atmospheric soundings in clear-sky conditions
GNSS-RO Residual Ionospheric Error (RIE): A New Method and Assessment
Measuring rainfall using microwave links: the influence of temporal sampling
Drone-based photogrammetry combined with deep learning to estimate hail size distributions and melting of hail on the ground
Mid-Atlantic Nocturnal Low-Level Jet Characteristics: A machine learning analysis of radar wind profiles
The High lAtitude sNowfall Detection and Estimation aLgorithm for ATMS (HANDEL-ATMS): a new algorithm for snowfall retrieval at high latitudes
Next-generation radiance unfiltering process for the Clouds and the Earth's Radiant Energy System instrument
Improved rain event detection in commercial microwave link time series via combination with MSG SEVIRI data
A directional surface reflectance climatology determined from TROPOMI observations
Investigation of gravity waves using measurements from a sodium temperature/wind lidar operated in multi-direction mode
An improved BRDF hotspot model and its use in VLIDORT for studying the impact of atmospheric scattering on hotspot directional signatures in the atmosphere
A multi-decadal time series of upper stratospheric temperature profiles from Odin-OSIRIS limb-scattered spectra
Observations of Tall-Building Wakes Using a Scanning Doppler Lidar
CALOTRITON: a convective boundary layer height estimation algorithm from ultra-high-frequency (UHF) wind profiler data
Enhancing consistency of microphysical properties of precipitation across the melting layer in dual-frequency precipitation radar data
Profiling the molecular destruction rates of temperature and humidity as well as the turbulent kinetic energy dissipation in the convective boundary layer
Forward operator for polarimetric radio occultation measurements
Assessing atmospheric gravity wave spectra in the presence of observational gaps
Endrit Shehaj, Stephen Leroy, Kerri Cahoy, Alain Geiger, Laura Crocetti, Gregor Moeller, Benedikt Soja, and Markus Rothacher
Atmos. Meas. Tech., 18, 57–72, https://doi.org/10.5194/amt-18-57-2025, https://doi.org/10.5194/amt-18-57-2025, 2025
Short summary
Short summary
This work investigates whether machine learning (ML) can offer an alternative to existing methods to map radio occultation (RO) products, allowing the extraction of information not visible in direct observations. ML can further improve the results of Bayesian interpolation, a state-of-the-art method to map RO observations. The results display improvements in horizontal and temporal domains, at heights ranging from the planetary boundary layer up to the lower stratosphere, and for all seasons.
Andreas Foth, Moritz Lochmann, Pablo Saavedra Garfias, and Heike Kalesse-Los
Atmos. Meas. Tech., 17, 7169–7181, https://doi.org/10.5194/amt-17-7169-2024, https://doi.org/10.5194/amt-17-7169-2024, 2024
Short summary
Short summary
Microwave radiometers are usually not able to provide atmospheric quantities such as temperature profiles during rain. We present a method based on a selection of specific frequencies and elevation angles from microwave radiometer observations. A comparison with a numerical weather prediction model shows the presented method allows low-level temperature profiles during rain to be resolved, with rain rates of up to 2.5 mm h−1,, which was not possible before with state-of-the-art retrievals.
Lev D. Labzovskii, Gerd-Jan van Zadelhoff, David P. Donovan, Jos de Kloe, L. Gijsbert Tilstra, Ad Stoffelen, Damien Josset, and Piet Stammes
Atmos. Meas. Tech., 17, 7183–7208, https://doi.org/10.5194/amt-17-7183-2024, https://doi.org/10.5194/amt-17-7183-2024, 2024
Short summary
Short summary
The Atmospheric Laser Doppler Instrument (ALADIN) on the Aeolus satellite was the first of its kind to measure high-resolution vertical profiles of aerosols and cloud properties from space. We present an algorithm that produces Aeolus lidar surface returns (LSRs), containing useful information for measuring UV reflectivity. Aeolus LSRs matched well with existing UV reflectivity data from other satellites, like GOME-2 and TROPOMI, and demonstrated excellent sensitivity to modeled snow cover.
Thomas Hocking, Thorsten Mauritsen, and Linda Megner
Atmos. Meas. Tech., 17, 7077–7095, https://doi.org/10.5194/amt-17-7077-2024, https://doi.org/10.5194/amt-17-7077-2024, 2024
Short summary
Short summary
The imbalance between the energy the Earth absorbs from the Sun and the energy the Earth emits back into space gives rise to climate change, but measuring the small imbalance is challenging. We simulate satellites in various orbits to investigate how well they sample the imbalance and find that the best option is to combine at least two satellites that see complementary parts of the Earth and cover the daily and annual cycles. This information is useful when planning future satellite missions.
Almudena Velázquez Blázquez, Carlos Domenech, Edward Baudrez, Nicolas Clerbaux, Carla Salas Molar, and Nils Madenach
Atmos. Meas. Tech., 17, 7007–7026, https://doi.org/10.5194/amt-17-7007-2024, https://doi.org/10.5194/amt-17-7007-2024, 2024
Short summary
Short summary
This paper focuses on the BMA-FLX processor, in which thermal and solar top-of-atmosphere radiative fluxes are obtained from longwave and shortwave radiances measured along track by the EarthCARE Broadband Radiometer (BBR). The BBR measurements, at three fixed viewing angles (fore, nadir, aft), are co-registered either at the surface or at a reference level. A combined flux from the three BRR views is obtained. The algorithm has been successfully validated against test scenes.
Wolf Knöller, Gholamhossein Bagheri, Philipp von Olshausen, and Michael Wilczek
Atmos. Meas. Tech., 17, 6913–6931, https://doi.org/10.5194/amt-17-6913-2024, https://doi.org/10.5194/amt-17-6913-2024, 2024
Short summary
Short summary
Three-dimensional (3D) wind velocity measurements are of major importance for the characterization of atmospheric turbulence. This paper presents a detailed study of the measurement uncertainty of a three-beam wind lidar designed for mounting on airborne platforms. Considering the geometrical constraints, the analysis provides quantitative estimates for the measurement uncertainty of all components of the 3D wind vector. As a result, we propose optimized post-processing for error reduction.
Bianca Adler, David D. Turner, Laura Bianco, Irina V. Djalalova, Timothy Myers, and James M. Wilczak
Atmos. Meas. Tech., 17, 6603–6624, https://doi.org/10.5194/amt-17-6603-2024, https://doi.org/10.5194/amt-17-6603-2024, 2024
Short summary
Short summary
Continuous profile observations of temperature and humidity in the lowest part of the atmosphere are essential for the evaluation of numerical weather prediction models and data assimilation for better weather forecasts. Such profiles can be retrieved from passive ground-based remote sensing instruments like infrared spectrometers and microwave radiometers. In this study, we describe three recent modifications to the retrieval framework TROPoe for improved temperature and humidity profiles.
Bernat Puigdomènech Treserras and Pavlos Kollias
Atmos. Meas. Tech., 17, 6301–6314, https://doi.org/10.5194/amt-17-6301-2024, https://doi.org/10.5194/amt-17-6301-2024, 2024
Short summary
Short summary
The paper presents a comprehensive approach to improve the geolocation accuracy of spaceborne radar and lidar systems, crucial for the successful interpretation of data from the upcoming EarthCARE mission. The paper details the technical background of the presented methods and various examples of geolocation analyses, including a short period of CloudSat observations when the star tracker was not operating properly and lifetime statistics from the CloudSat and CALIPSO missions.
Andreas Walbröl, Hannes J. Griesche, Mario Mech, Susanne Crewell, and Kerstin Ebell
Atmos. Meas. Tech., 17, 6223–6245, https://doi.org/10.5194/amt-17-6223-2024, https://doi.org/10.5194/amt-17-6223-2024, 2024
Short summary
Short summary
We developed retrievals of integrated water vapour (IWV), temperature profiles, and humidity profiles from ground-based passive microwave remote sensing measurements gathered during the MOSAiC expedition. We demonstrate and quantify the benefit of combining low- and high-frequency microwave radiometers to improve humidity profiling and IWV estimates by comparing the retrieved quantities to single-instrument retrievals and reference datasets (radiosondes).
Giulia Roccetti, Luca Bugliaro, Felix Gödde, Claudia Emde, Ulrich Hamann, Mihail Manev, Michael Fritz Sterzik, and Cedric Wehrum
Atmos. Meas. Tech., 17, 6025–6046, https://doi.org/10.5194/amt-17-6025-2024, https://doi.org/10.5194/amt-17-6025-2024, 2024
Short summary
Short summary
The amount of sunlight reflected by the Earth’s surface (albedo) is vital for the Earth's radiative system. While satellite instruments offer detailed spatial and temporal albedo maps, they only cover seven wavelength bands. We generate albedo maps that fully span the visible and near-infrared range using a machine learning algorithm. These maps reveal how the reflectivity of different land surfaces varies throughout the year. Our dataset enhances the understanding of the Earth's energy balance.
Sebastian Rhode, Peter Preusse, Jörn Ungermann, Inna Polichtchouk, Kaoru Sato, Shingo Watanabe, Manfred Ern, Karlheinz Nogai, Björn-Martin Sinnhuber, and Martin Riese
Atmos. Meas. Tech., 17, 5785–5819, https://doi.org/10.5194/amt-17-5785-2024, https://doi.org/10.5194/amt-17-5785-2024, 2024
Short summary
Short summary
We investigate the capabilities of a proposed satellite mission, CAIRT, for observing gravity waves throughout the middle atmosphere and present the necessary methodology for in-depth wave analysis. Our findings suggest that such a satellite mission is highly capable of resolving individual wave parameters and could give new insights into the role of gravity waves in general atmospheric circulation and atmospheric processes.
Suyoung Sim, Sungwon Choi, Daeseong Jung, Jongho Woo, Nayeon Kim, Sungwoo Park, Honghee Kim, Ukkyo Jeong, Hyunkee Hong, and Kyung-Soo Han
Atmos. Meas. Tech., 17, 5601–5618, https://doi.org/10.5194/amt-17-5601-2024, https://doi.org/10.5194/amt-17-5601-2024, 2024
Short summary
Short summary
This study evaluates the use of background surface reflectance (BSR) derived from a semi-empirical bidirectional reflectance distribution function (BRDF) model based on GEMS satellite images. Analysis shows that BSR provides improved accuracy and stability compared to Lambertian-equivalent reflectivity (LER). These results indicate that BSR can significantly enhance climate analysis and air quality monitoring, making it a promising tool for accurate environmental satellite applications.
Miguel Aldana, Seppo Pulkkinen, Annakaisa von Lerber, Matthew R. Kumjian, and Dmitri Moisseev
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-155, https://doi.org/10.5194/amt-2024-155, 2024
Revised manuscript accepted for AMT
Short summary
Short summary
Accurate KDP estimates are crucial in radar-based applications. We quantify the uncertainties of several publicly available KDP estimation methods for multiple rainfall intensities. We use C-band weather radar observations and employed a self-consistency KDP, estimated from reflectivity and differential reflectivity, as framework for the examination. Our study provides guidance in the performance, uncertainties and optimisation of the methods, focusing mainly on accuracy and robustness.
Daniel Durbin, Yadong Wang, and Pao-Liang Chang
Atmos. Meas. Tech., 17, 5397–5411, https://doi.org/10.5194/amt-17-5397-2024, https://doi.org/10.5194/amt-17-5397-2024, 2024
Short summary
Short summary
A method for determining drop size distributions (DSDs) for rain using radar measurements from two frequencies at two polarizations is presented. Following some preprocessing and quality control, radar measurements are incorporated into a model that uses swarm intelligence to seek the most suitable DSD to produce the input measurements.
Witali Krochin, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 17, 5015–5028, https://doi.org/10.5194/amt-17-5015-2024, https://doi.org/10.5194/amt-17-5015-2024, 2024
Short summary
Short summary
Atmospheric tides are global-scale oscillations with periods of a fraction of a day. Their observation in the middle atmosphere is challenging and rare, as it requires continuous measurements with a high temporal resolution. In this paper, temperature time series of a ground-based microwave radiometer were analyzed with a spectral filter to derive thermal tide amplitudes and phases in an altitude range of 25–50 km at the geographical locations of Payerne and Bern (Switzerland).
Thiruvengadam Padmanabhan, Guillaume Lesage, Ambinintsoa Volatiana Ramanamahefa, and Joël Van Baelen
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-117, https://doi.org/10.5194/amt-2024-117, 2024
Revised manuscript accepted for AMT
Short summary
Short summary
This study explores how the joints in a weather radar's protective cover affect its measurements. We developed a new method to correct these errors, improving the accuracy of the radar's data. Our method was tested during an intense cyclone on Reunion Island, demonstrating significant improvements in data accuracy. This research is crucial for enhancing weather predictions and understanding, particularly in challenging terrains.
Matteo Ottaviani, Gabriel Harris Myers, and Nan Chen
Atmos. Meas. Tech., 17, 4737–4756, https://doi.org/10.5194/amt-17-4737-2024, https://doi.org/10.5194/amt-17-4737-2024, 2024
Short summary
Short summary
We analyze simulated polarization observations over snow to investigate the capabilities of remote sensing to determine surface and atmospheric properties in snow-covered regions. Polarization measurements are demonstrated to aid in the determination of snow grain shape, ice crystal roughness, and the vertical distribution of impurities in the snow–atmosphere system, data that are critical for estimating snow albedo for use in climate models.
Yudong Gao, Lidou Huyan, Zheng Wu, and Bojun Liu
Atmos. Meas. Tech., 17, 4675–4686, https://doi.org/10.5194/amt-17-4675-2024, https://doi.org/10.5194/amt-17-4675-2024, 2024
Short summary
Short summary
A symmetric error model built by symmetric rain rates handles the non-Gaussian error structure of the reflectivity error. The accuracy and linearization of rain rates can further improve the Gaussianity.
José Alex Zenteno-Hernández, Adolfo Comerón, Federico Dios, Alejandro Rodríguez-Gómez, Constantino Muñoz-Porcar, Michaël Sicard, Noemi Franco, Andreas Behrendt, and Paolo Di Girolamo
Atmos. Meas. Tech., 17, 4687–4694, https://doi.org/10.5194/amt-17-4687-2024, https://doi.org/10.5194/amt-17-4687-2024, 2024
Short summary
Short summary
We study how the spectral characteristics of a solid-state laser in an atmospheric temperature profiling lidar using the Raman technique impact the temperature retrieval accuracy. We find that the spectral widening, with respect to a seeded laser, has virtually no impact, while crystal-rod temperature variations in the laser must be kept within a range of 1 K for the uncertainty in the atmospheric temperature below 1 K. The study is carried out through spectroscopy simulations.
Robert Reichert, Natalie Kaifler, and Bernd Kaifler
Atmos. Meas. Tech., 17, 4659–4673, https://doi.org/10.5194/amt-17-4659-2024, https://doi.org/10.5194/amt-17-4659-2024, 2024
Short summary
Short summary
Imagine you want to determine how quickly the pitch of a passing ambulance’s siren changes. If the vehicle is traveling slowly, the pitch changes only slightly, but if it is traveling fast, the pitch also changes rapidly. In a similar way, the wind in the middle atmosphere modulates the wavelength of atmospheric gravity waves. We have investigated the question of how strong the maximum wind may be so that the change in wavelength can still be determined with the help of wavelet transformation.
Qiang Guo, Yuning Liu, Xin Wang, and Wen Hui
Atmos. Meas. Tech., 17, 4613–4627, https://doi.org/10.5194/amt-17-4613-2024, https://doi.org/10.5194/amt-17-4613-2024, 2024
Short summary
Short summary
Non-linearity (NL) correction is a critical procedure to guarantee that the calibration accuracy of a spaceborne sensor approaches a reasonable level. Different from the classical method, a new NL correction method for a spaceborne Fourier transform spectrometer is proposed. To overcome the inaccurate linear coefficient from two-point calibration influencing NL correction, an iteration algorithm is established that is suitable for NL correction of both infrared and microwave sensors.
Yuanxin Pan, Grzegorz Kłopotek, Laura Crocetti, Rudi Weinacker, Tobias Sturn, Linda See, Galina Dick, Gregor Möller, Markus Rothacher, Ian McCallum, Vicente Navarro, and Benedikt Soja
Atmos. Meas. Tech., 17, 4303–4316, https://doi.org/10.5194/amt-17-4303-2024, https://doi.org/10.5194/amt-17-4303-2024, 2024
Short summary
Short summary
Crowdsourced smartphone GNSS data were processed with a dedicated data processing pipeline and could produce millimeter-level accurate estimates of zenith total delay (ZTD) – a critical atmospheric variable. This breakthrough not only demonstrates the feasibility of using ubiquitous devices for high-precision atmospheric monitoring but also underscores the potential for a global, cost-effective tropospheric monitoring network.
Almudena Velázquez Blázquez, Edward Baudrez, Nicolas Clerbaux, and Carlos Domenech
Atmos. Meas. Tech., 17, 4245–4256, https://doi.org/10.5194/amt-17-4245-2024, https://doi.org/10.5194/amt-17-4245-2024, 2024
Short summary
Short summary
The Broadband Radiometer measures shortwave and total-wave radiances filtered by the spectral response of the instrument. To obtain unfiltered solar and thermal radiances, the effect of the spectral response needs to be corrected for, done within the BM-RAD processor. Errors in the unfiltering are propagated into fluxes; thus, accurate unfiltering is required for their proper estimation (within BMA-FLX). Unfiltering errors are estimated to be <0.5 % for the shortwave and <0.1 % for the longwave.
Qihou Zhou, Yanlin Li, and Yun Gong
Atmos. Meas. Tech., 17, 4197–4209, https://doi.org/10.5194/amt-17-4197-2024, https://doi.org/10.5194/amt-17-4197-2024, 2024
Short summary
Short summary
We discuss several robust estimators to compute the variance of a normally distributed random variable to deal with interference. Compared to rank-based estimators, the methods based on the geometric mean are more accurate and are computationally more efficient. We apply three robust estimators to incoherent scatter power and velocity processing, along with the traditional sample mean estimator. The best estimator is a hybrid estimator that combines the sample mean and a robust estimator.
Zhao Shi, Yuxiang Wen, and Jianxin He
Atmos. Meas. Tech., 17, 4121–4135, https://doi.org/10.5194/amt-17-4121-2024, https://doi.org/10.5194/amt-17-4121-2024, 2024
Short summary
Short summary
The squall line is a type of convective system. Squall lines are often associated with damaging weather, so identifying and tracking squall lines plays an important role in early meteorological disaster warnings. A clustering-based method is proposed in this article. It can identify the squall lines within the radar scanning range with an accuracy rate of 95.93 %. It can also provide the three-dimensional structure and movement tracking results for each squall line.
Elizabeth N. Smith and Jacob T. Carlin
Atmos. Meas. Tech., 17, 4087–4107, https://doi.org/10.5194/amt-17-4087-2024, https://doi.org/10.5194/amt-17-4087-2024, 2024
Short summary
Short summary
Boundary-layer height observations remain sparse in time and space. In this study we create a new fuzzy logic method for synergistically combining boundary-layer height estimates from a suite of instruments. These estimates generally compare well to those from radiosondes; plus, the approach offers near-continuous estimates through the entire diurnal cycle. Suspected reasons for discrepancies are discussed. The code for the newly presented fuzzy logic method is provided for the community to use.
Laura Bianco, Bianca Adler, Ludovic Bariteau, Irina V. Djalalova, Timothy Myers, Sergio Pezoa, David D. Turner, and James M. Wilczak
Atmos. Meas. Tech., 17, 3933–3948, https://doi.org/10.5194/amt-17-3933-2024, https://doi.org/10.5194/amt-17-3933-2024, 2024
Short summary
Short summary
The Tropospheric Remotely Observed Profiling via Optimal Estimation physical retrieval is used to retrieve temperature and humidity profiles from various combinations of passive and active remote sensing instruments, surface platforms, and numerical weather prediction models. The retrieved profiles are assessed against collocated radiosonde in non-cloudy conditions to assess the sensitivity of the retrievals to different input combinations. Case studies with cloudy conditions are also inspected.
Björn Linder, Peter Preusse, Qiuyu Chen, Ole Martin Christensen, Lukas Krasauskas, Linda Megner, Manfred Ern, and Jörg Gumbel
Atmos. Meas. Tech., 17, 3829–3841, https://doi.org/10.5194/amt-17-3829-2024, https://doi.org/10.5194/amt-17-3829-2024, 2024
Short summary
Short summary
The Swedish research satellite MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is designed to study atmospheric waves in the mesosphere and lower thermosphere. These waves perturb the temperature field, and thus, by observing three-dimensional temperature fluctuations, their properties can be quantified. This pre-study uses synthetic MATS data generated from a general circulation model to investigate how well wave properties can be retrieved.
Gia Huan Pham, Shu-Chih Yang, Chih-Chien Chang, Shu-Ya Chen, and Cheng Yung Huang
Atmos. Meas. Tech., 17, 3605–3623, https://doi.org/10.5194/amt-17-3605-2024, https://doi.org/10.5194/amt-17-3605-2024, 2024
Short summary
Short summary
This research examines the characteristics of low-level GNSS radio occultation (RO) refractivity bias over ocean and land and its dependency on the RO retrieval uncertainty, atmospheric temperature, and moisture. We propose methods for estimating the region-dependent refractivity bias. Our methods can be applied to calibrate the refractivity bias under different atmospheric conditions and thus improve the applications of the GNSS RO data in the deep troposphere.
Sanja Dmitrovic, Johnathan W. Hair, Brian L. Collister, Ewan Crosbie, Marta A. Fenn, Richard A. Ferrare, David B. Harper, Chris A. Hostetler, Yongxiang Hu, John A. Reagan, Claire E. Robinson, Shane T. Seaman, Taylor J. Shingler, Kenneth L. Thornhill, Holger Vömel, Xubin Zeng, and Armin Sorooshian
Atmos. Meas. Tech., 17, 3515–3532, https://doi.org/10.5194/amt-17-3515-2024, https://doi.org/10.5194/amt-17-3515-2024, 2024
Short summary
Short summary
This study introduces and evaluates a new ocean surface wind speed product from the NASA Langley Research Center (LARC) airborne High-Spectral-Resolution Lidar – Generation 2 (HSRL-2) during the NASA ACTIVATE mission. We show that HSRL-2 surface wind speed data are accurate when compared to ground-truth dropsonde measurements. Therefore, the HSRL-2 instrument is able obtain accurate, high-resolution surface wind speed data in airborne field campaigns.
Laura M. Tomkins, Sandra E. Yuter, and Matthew A. Miller
Atmos. Meas. Tech., 17, 3377–3399, https://doi.org/10.5194/amt-17-3377-2024, https://doi.org/10.5194/amt-17-3377-2024, 2024
Short summary
Short summary
We have created a new method to better identify enhanced features in radar data from winter storms. Unlike the clear-cut features seen in warm-season storms, features in winter storms are often fuzzier with softer edges. Our technique is unique because it uses two adaptive thresholds that change based on the background radar values. It can identify both strong and subtle features in the radar data and takes into account uncertainties in the detection process.
Eileen Päschke and Carola Detring
Atmos. Meas. Tech., 17, 3187–3217, https://doi.org/10.5194/amt-17-3187-2024, https://doi.org/10.5194/amt-17-3187-2024, 2024
Short summary
Short summary
Little noise in radial velocity Doppler lidar measurements can contribute to large errors in retrieved turbulence variables. In order to distinguish between plausible and erroneous measurements we developed new filter techniques that work independently of the choice of a specific threshold for the signal-to-noise ratio. The performance of these techniques is discussed both by means of assessing the filter results and by comparing retrieved turbulence variables versus independent measurements.
Lei Liu, Natalia Bliankinshtein, Yi Huang, John R. Gyakum, Philip M. Gabriel, Shiqi Xu, and Mengistu Wolde
EGUsphere, https://doi.org/10.5194/egusphere-2024-1045, https://doi.org/10.5194/egusphere-2024-1045, 2024
Short summary
Short summary
This study evaluates and compares a new microwave hyperspectrometer with an infrared hyperspectrometer for clear-sky temperature and water vapor retrievals. The analysis reveals that the information content of the infrared hyperspectrometer exceeds that of the microwave hyperspectrometer and provides higher vertical resolution in ground-based zenith measurements. Leveraging the ground-airborne synergy between the two instruments yielded optimal-sounding results.
Dong L. Wu, Valery A. Yudin, Kyu-Myong Kim, Mohar Chattopadhyay, Lawrence Coy, Ruth S. Lieberman, C. C. Jude H. Salinas, Jae H. Lee, Jie Gong, and Guiping Liu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-51, https://doi.org/10.5194/amt-2024-51, 2024
Revised manuscript accepted for AMT
Short summary
Short summary
Radio occultation (RO) observations play an important role in monitoring climate changes and numerical weather forecasts. The residual ionospheric error (RIE) in RO measurements is critical to accurately retrieve atmospheric temperature and refractivity. This study shows that RIF impacts on temperature analysis are mainly confined to the polar stratosphere with amplitude of 1–4 K. These results further highlight the need for RO RIE correction in the modern data assimilation systems.
Luuk D. van der Valk, Miriam Coenders-Gerrits, Rolf W. Hut, Aart Overeem, Bas Walraven, and Remko Uijlenhoet
Atmos. Meas. Tech., 17, 2811–2832, https://doi.org/10.5194/amt-17-2811-2024, https://doi.org/10.5194/amt-17-2811-2024, 2024
Short summary
Short summary
Microwave links, often part of mobile phone networks, can be used to measure rainfall along the link path by determining the signal loss caused by rainfall. We use high-frequency data of multiple microwave links to recreate commonly used sampling strategies. For time intervals up to 1 min, the influence of sampling strategies on estimated rainfall intensities is relatively little, while for intervals longer than 5–15 min, the sampling strategy can have significant influences on the estimates.
Martin Lainer, Killian P. Brennan, Alessandro Hering, Jérôme Kopp, Samuel Monhart, Daniel Wolfensberger, and Urs Germann
Atmos. Meas. Tech., 17, 2539–2557, https://doi.org/10.5194/amt-17-2539-2024, https://doi.org/10.5194/amt-17-2539-2024, 2024
Short summary
Short summary
This study uses deep learning (the Mask R-CNN model) on drone-based photogrammetric data of hail on the ground to estimate hail size distributions (HSDs). Traditional hail sensors' limited areas complicate the full HSD retrieval. The HSD of a supercell event on 20 June 2021 is retrieved and contains > 18 000 hailstones. The HSD is compared to automatic hail sensor measurements and those of weather-radar-based MESHS. Investigations into ground hail melting are performed by five drone flights.
Maurice Roots, John T. Sullivan, and Belay Demoz
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-37, https://doi.org/10.5194/amt-2024-37, 2024
Revised manuscript accepted for AMT
Short summary
Short summary
This paper introduces a machine-learning approach to automatically isolate Nocturnal Low-Level Jets (NLLJs) using observations from Maryland’s Radar Wind Profiler (RWP) network. Initial findings identify 90 south-westerly NLLJs from May to September 2017–2021, showcasing core parameters and jet morphology. The research aims to establish a foundation for understanding the formation mechanisms of Mid-Atlantic NLLJs and their impact on air quality.
Andrea Camplani, Daniele Casella, Paolo Sanò, and Giulia Panegrossi
Atmos. Meas. Tech., 17, 2195–2217, https://doi.org/10.5194/amt-17-2195-2024, https://doi.org/10.5194/amt-17-2195-2024, 2024
Short summary
Short summary
The paper describes a new machine-learning-based snowfall retrieval algorithm for Advanced Technology Microwave Sounder observations developed to retrieve high-latitude snowfall events. The main novelty of the approach is the radiometric characterization of the background surface at the time of the overpass, which is ancillary to the retrieval process. The algorithm shows a unique capability to retrieve snowfall in the environmental conditions typical of high latitudes.
Lusheng Liang, Wenying Su, Sergio Sejas, Zachary Eitzen, and Norman G. Loeb
Atmos. Meas. Tech., 17, 2147–2163, https://doi.org/10.5194/amt-17-2147-2024, https://doi.org/10.5194/amt-17-2147-2024, 2024
Short summary
Short summary
This paper describes an updated process to obtain unfiltered radiation from CERES satellite instruments by incorporating the most recent developments in radiative transfer modeling and ancillary input datasets (e.g., realistic representation of land surface radiation and climatology of surface temperatures and aerosols) during the past 20 years. The resulting global mean of instantaneous SW and LW fluxes is changed by less than 0.5 W m−2 with regional differences as large as 2.0 W m−2.
Maximilian Graf, Andreas Wagner, Julius Polz, Llorenç Lliso, José Alberto Lahuerta, Harald Kunstmann, and Christian Chwala
Atmos. Meas. Tech., 17, 2165–2182, https://doi.org/10.5194/amt-17-2165-2024, https://doi.org/10.5194/amt-17-2165-2024, 2024
Short summary
Short summary
Commercial microwave links (CMLs) can be used for rainfall retrieval. The detection of rainy periods in their attenuation time series is a crucial processing step. We investigate the usage of rainfall data from MSG SEVIRI for this task, compare this approach with existing methods, and introduce a novel combined approach. The results show certain advantages for SEVIRI-based methods, particularly for CMLs where existing methods perform poorly. Our novel combination yields the best performance.
Lieuwe G. Tilstra, Martin de Graaf, Victor J. H. Trees, Pavel Litvinov, Oleg Dubovik, and Piet Stammes
Atmos. Meas. Tech., 17, 2235–2256, https://doi.org/10.5194/amt-17-2235-2024, https://doi.org/10.5194/amt-17-2235-2024, 2024
Short summary
Short summary
This paper introduces a new surface albedo climatology of directionally dependent Lambertian-equivalent reflectivity (DLER) observed by TROPOMI on the Sentinel-5 Precursor satellite. The database contains monthly fields of DLER for 21 wavelength bands at a relatively high spatial resolution of 0.125 by 0.125 degrees. The anisotropy of the surface reflection is handled by parameterisation of the viewing angle dependence.
Bing Cao and Alan Z. Liu
Atmos. Meas. Tech., 17, 2123–2146, https://doi.org/10.5194/amt-17-2123-2024, https://doi.org/10.5194/amt-17-2123-2024, 2024
Short summary
Short summary
A narrow-band sodium lidar measures atmospheric waves but is limited to vertical variations. We propose to utilize phase shifts among observations from different laser beams to derive horizontal wave information. Two gravity wave packets were identified by this method. Both waves were found to interact with thin evanescent layers, partially reflected, but transmitted energy to higher altitudes. The method can detect more medium-frequency gravity waves for similar lidar systems worldwide.
Xiaozhen Xiong, Xu Liu, Robert Spurr, Ming Zhao, Qiguang Yang, Wan Wu, and Liqiao Lei
Atmos. Meas. Tech., 17, 1965–1978, https://doi.org/10.5194/amt-17-1965-2024, https://doi.org/10.5194/amt-17-1965-2024, 2024
Short summary
Short summary
The term “hotspot” refers to the sharp increase in reflectance occurring when incident (solar) and reflected (viewing) directions coincide in the backscatter direction. The accurate simulation of hotspot directional signatures is important for many remote sensing applications, but current models typically require large values of computations to represent the hotspot accurately. This paper provides a numerically improved hotspot BRDF model that converges much faster and is used in VLIDORT.
Daniel Zawada, Kimberlee Dubé, Taran Warnock, Adam Bourassa, Susann Tegtmeier, and Douglas Degenstein
Atmos. Meas. Tech., 17, 1995–2010, https://doi.org/10.5194/amt-17-1995-2024, https://doi.org/10.5194/amt-17-1995-2024, 2024
Short summary
Short summary
There remain large uncertainties in long-term changes of stratospheric–atmospheric temperatures. We have produced a time series of more than 20 years of satellite-based temperature measurements from the OSIRIS instrument in the upper–middle stratosphere. The dataset is publicly available and intended to be used for a better understanding of changes in stratospheric temperatures.
Natalie E. Theeuwes, Janet F. Barlow, Antti Mannisenaho, Denise Hertwig, Ewan O'Connor, and Alan Robins
EGUsphere, https://doi.org/10.5194/egusphere-2024-937, https://doi.org/10.5194/egusphere-2024-937, 2024
Short summary
Short summary
A doppler lidar was placed in highly built-up area in London to measure wakes from tall buildings during a period of one year. We were able to detect wakes and assess their dependence on wind speed, wind direction, and atmospheric stability.
Alban Philibert, Marie Lothon, Julien Amestoy, Pierre-Yves Meslin, Solène Derrien, Yannick Bezombes, Bernard Campistron, Fabienne Lohou, Antoine Vial, Guylaine Canut-Rocafort, Joachim Reuder, and Jennifer K. Brooke
Atmos. Meas. Tech., 17, 1679–1701, https://doi.org/10.5194/amt-17-1679-2024, https://doi.org/10.5194/amt-17-1679-2024, 2024
Short summary
Short summary
We present a new algorithm, CALOTRITON, for the retrieval of the convective boundary layer depth with ultra-high-frequency radar measurements. CALOTRITON is partly based on the principle that the top of the convective boundary layer is associated with an inversion and a decrease in turbulence. It is evaluated using ceilometer and radiosonde data. It is able to qualify the complexity of the vertical structure of the low troposphere and detect internal or residual layers.
Kamil Mroz, Alessandro Battaglia, and Ann M. Fridlind
Atmos. Meas. Tech., 17, 1577–1597, https://doi.org/10.5194/amt-17-1577-2024, https://doi.org/10.5194/amt-17-1577-2024, 2024
Short summary
Short summary
In this study, we examine the extent to which radar measurements from space can inform us about the properties of clouds and precipitation. Surprisingly, our analysis showed that the amount of ice turning into rain was lower than expected in the current product. To improve on this, we came up with a new way to extract information about the size and concentration of particles from radar data. As long as we use this method in the right conditions, we can even estimate how dense the ice is.
Volker Wulfmeyer, Christoph Senff, Florian Späth, Andreas Behrendt, Diego Lange, Robert M. Banta, W. Alan Brewer, Andreas Wieser, and David D. Turner
Atmos. Meas. Tech., 17, 1175–1196, https://doi.org/10.5194/amt-17-1175-2024, https://doi.org/10.5194/amt-17-1175-2024, 2024
Short summary
Short summary
A simultaneous deployment of Doppler, temperature, and water-vapor lidar systems is used to provide profiles of molecular destruction rates and turbulent kinetic energy (TKE) dissipation in the convective boundary layer (CBL). The results can be used for the parameterization of turbulent variables, TKE budget analyses, and the verification of weather forecast and climate models.
Daisuke Hotta, Katrin Lonitz, and Sean Healy
Atmos. Meas. Tech., 17, 1075–1089, https://doi.org/10.5194/amt-17-1075-2024, https://doi.org/10.5194/amt-17-1075-2024, 2024
Short summary
Short summary
Global Navigation Satellite System (GNSS) polarimetric radio occultation (PRO) is a new type of GNSS observations that can detect heavy precipitation along the ray path between the emitter and receiver satellites. As a first step towards using these observations in numerical weather prediction (NWP), we developed a computer code that simulates GNSS-PRO observations from forecast fields produced by an NWP model. The quality of the developed simulator is evaluated with a number of case studies.
Mohamed Mossad, Irina Strelnikova, Robin Wing, and Gerd Baumgarten
Atmos. Meas. Tech., 17, 783–799, https://doi.org/10.5194/amt-17-783-2024, https://doi.org/10.5194/amt-17-783-2024, 2024
Short summary
Short summary
This numerical study addresses observational gaps' impact on atmospheric gravity wave spectra. Three methods, fast Fourier transform (FFT), generalized Lomb–Scargle periodogram (GLS), and Haar structure function (HSF), were tested on synthetic data. HSF is best for spectra with negative slopes. GLS excels for flat and positive slopes and identifying dominant frequencies. Accurately estimating these aspects is crucial for understanding gravity wave dynamics and energy transfer in the atmosphere.
Cited articles
Andrioli, V. F., Fritts, D. C., Batista, P. P., and Clemesha, B. R.: Improved
analysis of all-sky meteor radar measurements of gravity wave variances and
momentum fluxes, Ann. Geophys., 31, 889–908,
https://doi.org/10.5194/angeo-31-889-2013, 2013. a
Borchert, S., Zhou, G., Baldauf, M., Schmidt, H., Zängl, G., and Reinert, D.:
The upper-atmosphere extension of the ICON general circulation model
(version: ua-icon-1.0), Geosci. Model Dev., 12, 3541–3569,
https://doi.org/10.5194/gmd-12-3541-2019, 2019. a
Browning, K. A. and Wexler, R.: The determination of kinematic properties of a
wind field using Doppler radar, J. Appl. Meteorol., 7, 105–113,
https://doi.org/10.1175/1520-0450(1968)007<0105:TDOKPO>2.0.CO;2, 1968. a
Charuvil Asokan, H., Chau, J. L., Marino, R., Vierinen, J., Vargas, F., Urco, J. M., Clahsen, M., and Jacobi, C.: Study of second-order wind statistics in the mesosphere and lower thermosphere region from multistatic specular meteor radar observations during the SIMONe 2018 campaign, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2020-974, 2020. a, b, c
Chau, J. L. and Clahsen, M.: Empirical phase calibration for multi-static
specular meteor radars using a beam-forming approach, Radio Sci., 54, 60–71,
https://doi.org/10.1029/2018RS006741, 2019. a
Chau, J. L., Stober, G., Hall, C. M., Tsutsumi, M., Laskar, F. I., and
Hoffmann, P.: Polar mesospheric horizontal divergence and relative vorticity
measurements using multiple specular meteor radars, Radio Sci., 52,
811–828, https://doi.org/10.1002/2016RS006225, 2016RS006225, 2017. a, b, c, d, e, f, g
Chau, J. L., Urco, J. M., Vierinen, J. P., Volz, R. A., Clahsen, M., Pfeffer,
N., and Trautner, J.: Novel specular meteor radar systems using coherent MIMO
techniques to study the mesosphere and lower thermosphere, Atmos. Meas.
Tech., 12, 2113–2127, https://doi.org/10.5194/amt-12-2113-2019, 2019. a, b, c
Chau, J. L., Urco, J. M., Vierinen, J., Harding, B. J., Clahsen, M., Pfeffer,
N., Kuyeng, K. M., Milla, M. A., and Erickson, P. J.: Multistatic Specular
Meteor Radar Network in Peru: System Description and Initial Results, Earth
Space Sci., 8, e2020EA001293,
https://doi.org/10.1029/2020EA001293, 2021. a, b, c, d, e, f
Conte, J. F., Chau, J. L., Urco, J. M., Latteck, R., Vierinen, J., and
Salvador, J. O.: First studies of mesosphere and lower thermosphere dynamics
using a multistatic specular meteor radar network over southern Patagonia,
Earth Space Sci., 8, e2020EA001356,
https://doi.org/10.1029/2020EA001356, 2021. a, b
Cover, T. M. and Thomas, J. A.: Elements of Information Theory, John Wiley &
Sons, New York, 2006. a
Daley, R.: Atmospheric data analysis, Cambridge Univ. Press, Cambridge,
1991. a
Davis, S. C., Mabry, D. J., Koga, R., and George, J. S.: SEE and TID
Testing of Components for the Near Infrared Airglow Camera (NIRAC), in: 2018 IEEE Nuclear and Space Radiation Effects Conference (NSREC 2018), 2018 IEEE Nuclear and Space Radiation Effects Conference (NSREC 2018), Waikoloa Village, HI, 1–5,
https://doi.org/10.1109/NSREC.2018.8584268, 2018. a
Foreman-Mackey, D., Agol, E., Ambikasaran, S., and Angus, R.: Fast and Scalable
Gaussian Process Modeling with Applications to Astronomical Time Series,
Astron. J., 154, 220, https://doi.org/10.3847/1538-3881/aa9332, 2017. a
Fritts, D. C., Janches, D., Hocking, W. K., Mitchell, N. J., and Taylor, M. J.:
Assessment of gravity wave momentum flux measurement capabilities by meteor
radars having different transmitter power and antenna configurations, J.
Geophys. Res., 117, D10108, https://doi.org/10.1029/2011JD017174, 2012. a
Gardner, J., Pleiss, G., Weinberger, K. Q., Bindel, D., and Wilson, A. G.: GPyTorch: Blackbox Matrix-Matrix Gaussian Process Inference with GPU Acceleration, in: Advances in Neural Information Processing Systems, 31, 7576–7586, 2018. a
Harding, B. J., Makela, J. J., and Meriwether, J. W.: Estimation of mesoscale
thermospheric wind structure using a network of interferometers, J.
Geophys. Res.-Space, 120, 3928–3940,
https://doi.org/10.1002/2015JA021025, 2015. a, b
He, M. and Chau, J. L.: Mesospheric semidiurnal tides and near-12 h waves
through jointly analyzing observations of five specular meteor radars from
three longitudinal sectors at boreal midlatitudes, Atmos. Chem. Phys., 19,
5993–6006, https://doi.org/10.5194/acp-19-5993-2019, 2019. a
He, M., Chau, J. L., Stober, G., Li, G., Ning, B., and Hoffmann, P.: Relations
between semidiurnal tidal variants through diagnosing the zonal wavenumber
using a phase differencing technique based on two ground-based detectors, J.
Geophys. Res.-Atmos., 123, 4015–4026, https://doi.org/10.1002/2018JD028400, 2018. a
Hocking, W. K.: A new approach to momentum flux determinations using SKiYMET
meteor radars, Ann. Geophys., 23, 2433–2439,
https://doi.org/10.5194/angeo-23-2433-2005, 2005. a
Hoffmann, P., Becker, E., Singer, W., and Placke, M.: Seasonal variation of
mesospheric waves at northern middle and high latitudes, J.
Atmos. Sol.-Terr. Phys., 72, 1068–1079,
https://doi.org/10.1016/j.jastp.2010.07.002, 2010. a
Holdsworth, D. A., Reid, I. M., and Cervera, M. A.: Buckland Park all-sky
interferometric meteor radar, Radio Sci., 39, RS5009, https://doi.org/10.1029/2003RS003014,
2004. a, b, c
Hysell, D. L., Larsen, M. F., and Sulzer, M. P.: High time and height
resolution neutral wind profile measurements across the mesosphere/lower
thermosphere region using the Arecibo incoherent scatter radar, J.
Geophys. Res.-Space, 119, 2345–2358,
https://doi.org/10.1002/(ISSN)2169-9402, 2014. a
Journel, A. G. and Huijbregts, C. J.: Mining Geostatistics, Academic Press,
London, New York, 1978. a
Liu, H. L.: Quantifying gravity wave forcing using scale invariance, Nat.
Commun., 10, 1–12, https://doi.org/10.1038/s41467-019-10527-z, 2019. a
Marino, R., Rosenberg, D., Herbert, C., and Pouquet, A.: Interplay of waves and
eddies in rotating stratified turbulence and the link with kinetic-potential
energy partition, Europhys. Lett., 112, 49001,
https://doi.org/10.1209/0295-5075/112/49001, 2015. a
Matheron, G.: The Intrinsic Random Functions and Their Applications, Adv. Appl. Probab., 5, 439–468, https://doi.org/10.2307/1425829, 1973. a
Meriwether, J., Faivre, M., Fesen, C., Sherwood, P., and Veliz, O.: New
results on equatorial thermospheric winds and the midnight temperature
maximum, Ann. Geophys, 26, 447–466, 2008. a
Mitchell, N. J., Middleton, H. R., Beard, A. G., Williams, P. J. S., and
Muller, H. G.: The 16-day planetary wave in the mesosphere and lower
thermosphere, Ann. Geophys., 17,
1447–1456, 1999. a
Mitchell, N. J., Pancheva, D., Middleton, H. R., and Hagan, M. E.: Mean winds
and tides in the Arctic mesosphere and lower thermosphere, J. Geophys.
Res.-Space, 107, 1004, https://doi.org/10.1029/2001JA900127, 2002. a
Murphy, D. J.: Observations of a nonmigrating component of the semidiurnal tide
over Antarctica, J. Geophys. Res., 108, 4241, https://doi.org/10.1029/2002JD003077, 2003. a
Murphy, D. J., Forbes, J. M., Walterscheid, R. L., Hagan, M. E., Avery, S. K.,
Aso, T., Fraser, G. J., Fritts, D. C., Jarvis, M. J., J., M. A., Riggin,
D. M., Tsutsumi, M., and Vincent, R. A.: A climatology of tides in the
antarctic mesosphere and lower thermosphere, J. Geophys. Res.-Atmos., 111,
1–17, https://doi.org/10.1029/2005JD006803, 2006. a
Nicolls, M., Cosgrove, R., and Bahcivan, H.: Estimating the vector electric
field using monostatic, multibeam incoherent scatter radar measurements,
Radio Sci., 49, 1124–1139, https://doi.org/10.1002/2014RS005519, 2014. a
Pancheva, D., Mitchell, N., Clark, R. R., Drobjeva, J., and Lastovicka, J.:
Variability in the maximum height of the ionospheric F2-layer over
Millstone Hill (September 1998 to March 2000); influence from below and
above, Ann. Geophys, 20, 1807—1819, 2002. a
Placke, M., Hoffmann, P., Latteck, R., and Rapp, M.: Gravity wave momentum
fluxes from MF and meteor radar measurements in the polar MLT region,
J. Geophys. Res.-Space, 120, 736–750,
https://doi.org/10.1002/2014JA020460, 2015. a
Roberts, B. C. and Larsen, M. F.: Structure function analysis of chemical
tracer trails in the mesosphere‐lower thermosphere region, J.
Geophys. Res., 119, 6368–6375, https://doi.org/10.1002/2013JD020796, 2014. a
Sandford, D. J., Muller, H. G., and Mitchell, N. J.: Observations of lunar tides in the mesosphere and lower thermosphere at Arctic and middle latitudes, Atmos. Chem. Phys., 6, 4117–4127, https://doi.org/10.5194/acp-6-4117-2006, 2006. a
Scheuerer, M., Schaback, R., and Schlather, M.: Interpolation of Spatial Data –
A Stochastic or a Deterministic Problem?, Europ. J. Appl.
Mathemat., 24, 601–629,
https://doi.org/10.1017/S0956792513000016, 2013. a
Spargo, A. J., Reid, I. M., and MacKinnon, A. D.: Multistatic meteor radar
observations of gravity-wave–tidal interaction over southern Australia,
Atmos. Meas. Tech., 12, 4791–4812,
https://doi.org/10.5194/amt-12-4791-2019, 2019. a
Stober, G. and Chau, J. L.: A multistatic and multifrequency novel approach for
specular meteor radars to improve wind measurements in the MLT region,
Radio Sci., 50, 431–442, https://doi.org/10.1002/2014RS005591, 2014RS005591, 2015. a
Urco, J. M., Chau, J. L., Milla, M. A., Vierinen, J. P., and Weber, T.:
Coherent MIMO to Improve Aperture Synthesis Radar Imaging of Field-Aligned
Irregularities: First Results at Jicamarca, IEEE Trans. Geosci.
Remote Sens., 56, 2980–2990, https://doi.org/10.1109/TGRS.2017.2788425, 2018. a
Urco, J. M., Chau, J. L., Weber, T., and Latteck, R.: Enhancing the
spatio-temporal features of polar mesosphere summer echoes using coherent
MIMO and radar imaging at MAARSY, Atmos. Meas. Tech., 12,
955–969, https://doi.org/10.5194/amt-12-955-2019, 2019a. a
Urco, J. M., Chau, J. L., Weber, T., Vierinen, J., and Volz, R.: Sparse signal
recovery in MIMO specular meteor radars with waveform diversity, IEEE
Trans. Geosci. Remote Sens., 57, 10088–10098, https://doi.org/10.1029/2019EA000570,
2019b. a
Vargas, F., Chau, J. L., Charuvil Asokan, H., and Gerding, M.: Mesospheric gravity wave activity estimated via airglow imagery, multistatic meteor radar, and SABER data taken during the SIMONe–2018 campaign, Atmos. Chem. Phys., 21, 13631–13654, https://doi.org/10.5194/acp-21-13631-2021, 2021. a, b
Vierinen, J., Chau, J. L., Pfeffer, N., Clahsen, M., and Stober, G.: Coded
continuous wave meteor radar, Atmos. Meas. Tech., 9,
829–839, https://doi.org/10.5194/amt-9-829-2016, 2016. a
Vierinen, J., Chau, J. L., Asokan, H. C., Urco, J., Clahsen, M., Avsarkisov,
V., Marino, R., and Volz, R.: Observing mesospheric turbulence with specular
meteor radars: A novel method for estimating second order statistics of wind
velocity, Earth Space Sci., 6, 1171–1195, https://doi.org/10.1029/2019EA000570, 2019. a, b, c, d, e
Virtanen, P., Gommers, R., Oliphant, T. E., Haberland, M., Reddy, T.,
Cournapeau, D., Burovski, E., Peterson, P., Weckesser, W., Bright, J., van
der Walt, S. J., Brett, M., Wilson, J., Millman, K. J., Mayorov, N., Nelson,
A. R. J., Jones, E., Kern, R., Larson, E., Carey, C. J., Polat, İ., Feng,
Y., Moore, E. W., VanderPlas, J., Laxalde, D., Perktold, J., Cimrman, R.,
Henriksen, I., Quintero, E. A., Harris, C. R., Archibald, A. M., Ribeiro,
A. H., Pedregosa, F., van Mulbregt, P., SciPy 1.0 Contributors,
Vijaykumar, A., Bardelli, A. P., Rothberg, A., Hilboll, A., Kloeckner, A.,
Scopatz, A., Lee, A., Rokem, A., Woods, C. N., Fulton, C., Masson, C.,
Häggström, C., Fitzgerald, C., Nicholson, D. A., Hagen, D. R.,
Pasechnik, D. V., Olivetti, E., Martin, E., Wieser, E., Silva, F., Lenders,
F., Wilhelm, F., Young, G., Price, G. A., Ingold, G.-L., Allen, G. E., Lee,
G. R., Audren, H., Probst, I., Dietrich, J. P., Silterra, J., Webber, J. T.,
Slavič, J., Nothman, J., Buchner, J., Kulick, J., Schönberger,
J. L., de Miranda Cardoso, J. V., Reimer, J., Harrington, J.,
Rodríguez, J. L. C., Nunez-Iglesias, J., Kuczynski, J., Tritz, K.,
Thoma, M., Newville, M., Kümmerer, M., Bolingbroke, M., Tartre, M., Pak,
M., Smith, N. J., Nowaczyk, N., Shebanov, N., Pavlyk, O., Brodtkorb, P. A.,
Lee, P., McGibbon, R. T., Feldbauer, R., Lewis, S., Tygier, S., Sievert, S.,
Vigna, S., Peterson, S., More, S., Pudlik, T., Oshima, T., Pingel, T. J.,
Robitaille, T. P., Spura, T., Jones, T. R., Cera, T., Leslie, T., Zito, T.,
Krauss, T., Upadhyay, U., Halchenko, Y. O., and Vázquez-Baeza, Y.:
SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python,
Nat. Method., 17, 261–272, https://doi.org/10.1038/s41592-019-0686-2, 2020.
a
Volz, R., Chau, J. L., Erickson, P. J., Vierinen, J. P., Urco, J. M., and
Clahsen, M.: Meteor Observations and Wind Estimates from the Northern
Germany SIMONe Radar Network on November 5, 2018, Zenodo [data set],
https://doi.org/10.5281/zenodo.5550854, 2021. a
Wahlström, N., Kok, M., Schön, T. B., and Gustafsson, F.: Modeling
magnetic fields using Gaussian processes, in: 2013 IEEE International
Conference on Acoustics, Speech and Signal Processing (ICASSP), Vancouver, BC, Canada, 3522–3526,
https://doi.org/10.1109/ICASSP.2013.6638313, 2013. a
Wilson, A. and Nickisch, H.: Kernel Interpolation for Scalable Structured Gaussian Processes (KISS-GP), in: Proceedings of the 32nd International Conference on Machine Learning, International Conference on Machine Learning, Lille, France, 1775–1784, 2015. a
Short summary
We introduce a new way of estimating winds in the upper atmosphere (about 80 to 100 km in altitude) from the observed Doppler shift of meteor trails using a statistical method called Gaussian process regression. Wind estimates and, critically, the uncertainty of those estimates can be evaluated smoothly (i.e., not gridded) in space and time. The effective resolution is set by provided parameters, which are limited in practice by the number density of the observed meteors.
We introduce a new way of estimating winds in the upper atmosphere (about 80 to 100 km in...
